import React, { useState } from 'react'

export default function App() {
  // console.log('app里面的代码执行了')
  const [count, setCount] = useState(0)
  // const [msg, setMsg] = useState('123')
  // const [list, setList] = useState([])

  function handle() {
    setCount(count + 1)
    // setCount(count + 2)
    // setCount(count + 3)
  }
  return (
    <div>
      {count}
      <button onClick={handle}>+</button>
    </div>
  )
}
